It is the purpose of this research proposal to investigate the alpha-D-galactosyl-containing glycoproteins which occur as surface components on Ehrlich ascites tumor cells. These glycoproteins will be isolated from a cell membrane fraction by affinity chromatography on a Bandeiraea simplicifolia lectin column. Ehrlich ascites tumor cells are agglutinated by the B. simplicifolia lectin, a plant seed agglutinin which exhibits a high degree of specificity for alpha-D-galactopyranosyl end units as they occur on polysaccharides and glycoproteins. The glycoproteins will be subjected to physical, chemical and immunochemical characterization. Chemical and enzymatic alteration of the carbohydrate portion of intact Ehrlich ascites tumor cells will be carried out and the growth pattern of the cells studied. Immunological studies directed toward host rejection of growth retardation of murine ascites tumor cells will also be carried out. A search for alpha-D-galactosyl-containing glycoproteins in other normal and tumor cells will be conducted using fluorescein-labeled B. simplicifolia lectin.